I still have a set of bias plys mounted on some 15 x 7 Buick mags.... I bought them new in the 1980's!
Cooper makes the Cobra series of performance tires. White letters and a good performing tire for a musclecar. There were some recent promotions on eBay for a set of 4 bought from Discount Tire. Think it was a $100 rebate. This week there's a $75 rebate.
Mickey Thompson also has white-lettered musclecar tires. MT is owned by Cooper Tire, but I don't know if they share the same engineering. A great looking tire tho.
Those Cragars likely won't fit in the back.... looks like a deep-dish rim. A 275 should fit, but wheel backspace needs to be perfect.